Recently, in order to increase the storage capacity of the magnetic storage apparatus which is typified by a magnetic disk drive, various measures have been proposed to improve the recording density of the magnetic recording medium which is typified by a magnetic disk. For example, the flying height (or distance) of the head slider, mounted with a head element, from the magnetic recording medium has been reduced to several nm. As the flying height of the head slider decreases to such a small amount, a lubricant forming a lubricant layer that is provided on the surface of the magnetic recording medium is more easily adsorbed on the head slider surface. For example, when the head slider vibrates and accidentally makes contact with the surface of the magnetic recording medium or, the lubricant evaporates from the surface of the magnetic recording medium, the lubricant is adsorbed on the surface (hereinafter referred to as a medium opposing surface) of the head slider which opposes (or confronts) the surface of the magnetic recording medium. When the lubricant is adsorbed on the medium opposing surface of the head slider, the adsorbed lubricant may form a lump and fall on the magnetic recording medium. If the lump of the adsorbed lubricant falls off the head slider onto the magnetic recording medium, the surface of the magnetic recording medium will be contaminated, and the lump of the adsorbed lubricant may interfere with the stable floating of the head slider or damage the head element.
In the case of the magnetic disk drive, an air flow is generated between the head slider and the magnetic disk by the rotating magnetic disk. Hence, it is conceivable to employ a structure (hereinafter referred to as a lubricant contamination preventing structure) which uses this air flow to make it more difficult for the lubricant to be adsorbed on and form the lump of the adsorbed lubricant the medium opposing surface of the head slider. However, the air flow flows from an upstream side towards a downstream side of the head slider. For this reason, even in the case of the head slider having the lubricant contamination preventing structure, the lubricant is adsorbed on an end surface (hereinafter referred to as an outlet end surface) which extends in a perpendicular direction from the medium opposing surface at the downstream side of the head slider. In other words, even if the lubricant adsorbed on the medium opposing surface of the head slider is continuously ejected outside the medium opposing surface by the air flow before the adsorbed lubricant forms the lump, a portion of the lubricant ejected from the medium opposing surface transpires to the air, and a portion of the ejected lubricant is adsorbed on the outlet end surface by a wraparound behavior.
When the lubricant is adsorbed on the outlet end surface of the head slider, the adsorbed lubricant may form a lump and fall onto the magnetic recording medium. In this case, the surface of the magnetic recording medium will be contaminated by the lump of the lubricant, and the lump may interfere with the stable floating of the head slider. In addition, when a balance of the shear stress or pressure between the head slider and the magnetic disk changes during a head seek or the like, the lubricant adsorbed on the outlet end surface of the head slider may flow in reverse and each the medium opposing surface of the head slider.
Medium opposing surfaces having various shapes have been proposed, as may be seen from Japanese Laid-Open Patent Publications No. 10-11731 and No. 2003-109340, for example.
Therefore, according to the conventional magnetic storage apparatus, the lubricant forming the lubricant layer that is provided on the surface of the magnetic recording medium is easily adsorbed on the outlet end surface of the head slider.